[The] coalition between social conservatives and economic libertarians (who tend to be socially moderate to liberal), served the GOP well from 1964 to 2006. It gave the party eight years of Ronald Reagan and 12 years of a Republican Congress. But the Bush years have proven to be one long pulling apart. And, in a matter of days, we may just see the final snap.

The Cato Institute has done excellent work over the last few years tracking the shift in the libertarian vote—the roughly 10 percent to 15 percent of the American public that can be categorized as fiscally conservative and socially liberal.

Based on an analysis of the American National Election Studies, Cato found that between 2000 and 2004, there was a substantial flight of libertarians away from the Republican Party and toward the Democrats. While libertarians preferred Bush by a margin of 52 points over Al Gore in 2000, that margin shrank to 21 points in 2004, when many libertarians—disaffected by the Iraq war, massive GOP spending increases, and the campaign against gay marriage—switched to John Kerry.

Polling on libertarian voters is somewhat sparse during elections, but there are a couple of data points and some broad trends that can give us an idea of where things stand now. An early October Zogby Interactive poll found that self-identified libertarians (about 6 percent of the poll’s sample) give McCain only 36 percent of their vote, lower than the 45 percent and 42 percent Zogby found them giving Bush in the last two elections. The libertarian voters claim to be defecting mainly to Libertarian Party candidate Bob Barr and other third-party candidates, not to Obama. A Gallup poll conducted in September, which identified libertarian-minded voters with a series of ideological questions about the role of government in the economy and society (pegging them at around 23 percent of the electorate), found that only 43 percent of these voters plan pull the lever for McCain, slightly fewer than did for Bush in 2004. The Gallup poll also finds a significant uptick in libertarians planning to vote third-party, with 3.5 percent supporting Barr.

The GOP has lost these libertarian Republicans, Sager asserts, because it has become a one-note party:

Why would libertarians abandon McCain? After all, they believe in low taxes—and McCain is the one promising those. And if they’re concerned about social issues, well, McCain’s never shown much of a stomach for cultural warfare.

That is, of course, until now.

The real McCain, whoever that is or was, may still believe that major swathes of the Religious Right represent “agents of intolerance” in our politics. But he has decided to stake both his election and the Republican Party’s future upon them—from the barely coded racial refrain of “Who is Barack Obama?,” to the rallies with shouts of “terrorist” and “kill him,” to the corrosive choice of pipeline-prayer Sarah Palin as his running mate and heir apparent.

Tax cuts or no tax cuts, a party that can be roused in time of deep crisis only by fear and tribalism—a party that a supposed moderate is now deeding to its most extreme elements—can scarcely serve as a safe home to liberty or the voters who cherish it.

None of this is surprising, of course, because Republicans have been taking the libertarian, fiscally conservative oriented wing of their party for granted for quite some time now. While they pander to the religious right and social conservatives on a regular basis, they have spent the past eight years governing more like Democrats and Republicans and are leaving the nation with the legacy of a $ 10 trillion debt. And then, in what may end up being a grand act of political suicide, they nominate for President a man who clearly doesn’t give a crap about limited government in practice and let him pick a running mate who quite obviously doesn’t know what her job would be if she did manage to become Vice-President.

A party can ignore an important segment of swing voters for only so long — four-to-eight-years in the case of most right-leaning libertarians — before they finally become disaffected. Can the Republicans win us back?

Time after time, those of us who do believe in limited government, individual liberty, and fiscal responsibility are told that we have to accept the crappy nominees that we’re faced with “for the good of the party.”

Well, you know what ? I’m sick of it.

I’m sick of accepting the idea that politicians who have demonstrated time after time that they aren’t going to fulfill the promises they make should be re-elected to office. I’m sick of having Presidential candidates like Bob Dole, George W. Bush, and John McCain shoved down my throat. And, I’m sick of being told to vote for the lesser of two evils.

That’s why, when November comes along, I’m voting for Bob Barr for President, or I won’t be voting for President at all. When it comes to lesser offices, I’ll vote for candidates who actually believe in limited government and free markets regardless of which party they belong to.

The Republican Party can have my vote back when, and if, they earn it.